Clothes dryer using far-infrared heating and clothes-drying control method thereof

ABSTRACT

Provided are a clothes dryer using far-infrared heating and a clothes-drying control method thereof. The clothes dryer using far-infrared heating includes a clothes-drying drum, and further includes at least one far-infrared heater, a humidity sensor for detecting exhaust humidity of the clothes-drying drum, a relay and a controller having an output end connected with the relay; where all the far-infrared heaters are connected with a power supply through the relay; a first temperature sensor is mounted inside one of the far-infrared heaters; the first temperature sensor and the humidity sensor are connected with an input end of the controller; and the controller controls on and off of the relay according to a received temperature signal or humidity signal. A control system described above simplifies a circuit, and also saves cost.

TECHNICAL FIELD

The present disclosure relates to the field of clothes dryers, and inparticular to a clothes dryer using far-infrared heating and aclothes-drying control method thereof.

BACKGROUND

In the existing art, some clothes dryers or washing-drying integratedmachines use a far-infrared heating technology to dry clothes.Specifically, far-infrared heaters are arranged on or outside dryingdrums of the clothes dryers or the washing-drying integrated machines;the far-infrared heaters can emit far-infrared rays; the far-infraredrays have an energy characteristic of being absorbed by water but notabsorbed by air; therefore, the far-infrared rays are radiated tointeriors of the drying drums, are absorbed by water in heated objects,and are directly converted into a heat energy for converting the waterin the heated objects into water vapor to be drained out.

However, the existing clothes dryers or washing-drying integratedmachines use the far-infrared heating technology; on and off of a groupof far-infrared heaters are usually controlled by a relay arranged on aPCB (Printed Circuit Board); a temperature controller is mounted neareach of the far-infrared heaters to prevent that the temperature of thefar-infrared heater is too high; and a temperature sensor is arranged inthe drying drum to control that the temperature inside the drum is notexcessive. As a result, if an existing far-infrared heating control modeis used, one relay and one temperature controller need to be configuredfor each far-infrared heater, and multiple groups of relays andtemperature controllers need to be arranged in the entire clothes dryeror washing-drying integrated machine, to result in complicated circuitsand waste of cost.

The far-infrared heaters are made of TCM (Tin Ceramic Membrane)materials; the TCM is a novel functional ceramic composite electricheating material, has characteristics of converting electric energy intothe heat energy and then converting the heat energy into thefar-infrared rays, can be made into low-temperature andmiddle-temperature high-efficiency far-infrared components, can producerich long-wavelength far-infrared rays, is a pioneering, energy-savingand most advanced high-technology novel product, has thermal efficiencyup to 92%, saves electricity by 20%-30% compared with conventionalelectric heating components, and fully complies with environmentalprotection requirements as a clean energy. When the far-infrared heatersare used in the clothes dryers or washing-drying integrated machines fordrying the clothes, since a power density of the far-infrared heaters isrelatively low and large heating areas are required, single-piece powerof the existing far-infrared heaters is 200-400 W generally, e.g., anordinary 5 kg clothes dryer at least needs 3-6 far-infrared heaters; andif the existing heating control mode is used, one relay and onetemperature controller need to be configured for each far-infraredheater, i.e., 3-6 groups of relays and temperature controllers arerequired, to result in complicated circuits and waste of cost.

Based on the above descriptions, there is an urgent need for a novelfar-infrared clothes-drying control system, to solve problems ofcomplicated circuits of the control system and waste of cost in theexisting art.

SUMMARY

In view of this, an objective of the present disclosure is to provide aclothes dryer using far-infrared heating; and the clothes dryer onlyneeds to be configured with one relay and one temperature controller tomonitor all far-infrared heaters, thereby simplifying circuits andsaving cost.

Another objective of the present disclosure is to provide aclothes-drying control method using far-infrared heating; the method isapplied to the above clothes dryer using far-infrared heating; and thecontrol method is simple and easy to operate.

Embodiments of the present disclosure adopt following technicalsolutions.

A clothes dryer using far-infrared heating includes a clothes-dryingdrum, and further includes at least one far-infrared heater, a humiditysensor for detecting exhaust humidity of the clothes-drying drum, arelay and a controller having an output end connected with the relay;where all the far-infrared heaters are connected with a power supplythrough the relay; a first temperature sensor is mounted inside one ofthe far-infrared heaters; the first temperature sensor and the humiditysensor are connected with an input end of the controller; and thecontroller controls on and off of the relay according to a receivedtemperature signal or humidity signal.

The clothes dryer using far-infrared heating further may include atleast one second temperature sensor for detecting temperature inside theclothes-drying drum; and the second temperature sensor is connected withthe input end of the controller.

The second temperature sensor may be arranged at an air outlet of theclothes dryer.

The humidity sensor may be arranged at the air outlet of the clothesdryer.

A fan may be arranged at an air inlet of the clothes dryer; power of thefan is 10-20 W; and the fan is connected with the controller.

Mounting holes may be arranged in the clothes-drying drum; and thefar-infrared heaters are mounted in the mounting holes for heatinginterior of the clothes-drying drum.

At least one group of hole arrays may be arranged on the clothes-dryingdrum; each group of the hole arrays is composed of a plurality of holes;and the far-infrared heaters are arranged outside the hole arrays, andcan heat interior of the clothes-drying drum through the hole arrays.

A clothes-drying control method using far-infrared heating, applied tothe clothes dryer using far-infrared heating according to a first itemand includes the following steps:

in S11, detecting, by a first temperature sensor, temperature in afar-infrared heater and transmitting the temperature to a controller inthe form of signal; meanwhile detecting, by a humidity sensor, humidityof gas in a clothes-drying drum and transmitting the humidity to thecontroller in the form of signal;

in S12, comparing, by the controller, the received humidity value with apreset humidity value; executing a step S14 when the humidity value isgreater than the preset humidity value; and executing a step S13 whenthe humidity value is less than or equal to the preset humidity value;

in S13, controlling a relay to be in an off state by the controller;

in S14, comparing, by the controller, the received temperature in thefar-infrared heater with a preset upper limit temperature Tmax1 and apreset lower limit temperature Tmin1; executing the step S13 when thetemperature in the far-infrared heater is higher than the preset upperlimit temperature Tmax1; and executing a step S15 when the temperaturein the far-infrared heater is lower than the preset lower limittemperature Tmin1; and

in S15, controlling the relay to be in an on state by the controller.

A clothes-drying control method using far-infrared heating, applied tothe clothes dryer using far-infrared heating according to a second itemand includes the following steps:

in S21, detecting, by a first temperature sensor, temperature in afar-infrared heater and transmitting the temperature to a controller inthe form of signal; detecting, by a humidity sensor, humidity of gas ina clothes-drying drum and transmitting the humidity to the controller inthe form of signal; meanwhile detecting, by a second temperature sensor,the temperature in the clothes-drying drum and transmitting thetemperature to the controller in the form of signal;

in S22, comparing, by the controller, the received humidity value with apreset humidity value; executing a step S24 when the humidity value isgreater than the preset humidity value; and executing a step S23 whenthe humidity value is less than or equal to the preset humidity value;

in S23, controlling a relay to be in an off state by the controller;

in S24, comparing, by the controller, the received temperature in thefar-infrared heater with a preset upper limit temperature Tmax1 and apreset lower limit temperature Tmin1, and comparing the receivedtemperature in the clothes-drying drum with a preset upper limittemperature Tmax2 and a preset lower limit temperature Tmin2; executingthe step S23 when at least one of conditions that the temperature in thefar-infrared heater is higher than the preset upper limit temperatureTmax1, and the temperature in the clothes-drying drum is higher than thepreset upper limit temperature Tmax2 is satisfied; and executing a stepS15 when at least one of conditions that the temperature in thefar-infrared heater is lower than the preset lower limit temperatureTmin1, and the temperature in the clothes-drying drum is lower than thepreset lower limit temperature Tmin2 is satisfied; and

in S25, controlling the relay to be in an on state by the controller.

The technical solutions proposed by embodiments of the presentdisclosure have beneficial effects that: all the far-infrared heatersare connected with the power supply through one relay, i.e., the on andoff of all relays are controlled by one relay; one first temperaturesensor is mounted inside one of the far-infrared heaters; the firsttemperature sensor and the humidity sensor for detecting the exhausthumidity of the clothes-drying drum are connected with the controller;the controller controls the on and off of the relay according to thereceived temperature signal or humidity signal; therefore, a controlsystem described above simplifies circuits and saves cost.

BRIEF DESCRIPTION OF DRAWINGS

In order to more clearly illustrate the technical solutions inembodiments of the present disclosure, drawings which are required to beused in the descriptions of embodiments of the present disclosure arebriefly introduced hereinafter. It is apparent that the drawingsdescribed below are only some embodiments of the present disclosure; forthose ordinary skilled in the art, other drawings can also be obtainedin accordance with contents and these drawings of embodiments of thepresent disclosure without paying creative efforts.

FIG. 1 is a schematic structural diagram illustrating a far-infraredclothes-drying control system provided by device embodiments of thepresent disclosure;

FIG. 2 is a flow chart illustrating a clothes-drying control methodprovided by method embodiments of the present disclosure; and

FIG. 3 is a flow chart illustrating a mode of a clothes-drying controlmethod provided by method embodiments of the present disclosure.

In the figures:

1: Far-infrared heater; 2: Controller; 3: Relay; 4: Power supply; 5:First temperature sensor; 6: Humidity sensor; 7: Second temperaturesensor; 8: Fan.

DETAILED DESCRIPTION

In order to make solved technical problems, adopted technical solutionsand achieved technical effects of the present disclosure clearer, thetechnical solutions of embodiments of the present disclosure are furtherdescribed in detail in combination with the drawings below. Apparently,the described embodiments are merely some embodiments of the presentdisclosure, rather than all embodiments. All other embodiments obtainedby those skilled in the art without paying creative efforts fall withina protection scope of the present disclosure, based on embodiments ofthe present disclosure.

Embodiments of Device

The far-infrared heater provided by the present disclosure can beapplied to a washing-drying integrated machine and can also be appliedto a clothes dryer; and the clothes dryer is introduced below as anexample. The clothes dryer includes a tank body and a far-infraredclothes-drying control system; the far-infrared clothes-drying controlsystem includes a clothes-drying drum, which is rotatably arrangedinside the tank body. FIG. 1 is a schematic structural diagramillustrating the far-infrared clothes-drying control system provided bydevice embodiments of the present disclosure. As shown in FIG. 1, thefar-infrared clothes-drying control system further includes at least onefar-infrared heater 1, a humidity sensor 6 for detecting exhausthumidity of the clothes-drying drum, a relay 3 and a controller 2 havingan output end connected with the relay 3; the controller 2 is connectedwith a power supply 4; all the infrared heaters 1 are connected with thepower supply 4 through the relay 3; a first temperature sensor 5 ismounted inside one of the far-infrared heaters 1; the first temperaturesensor 5 and the humidity sensor 6 are connected with an input end ofthe controller 2; and the controller 2 controls on and off of the relay3 according to a received temperature signal or humidity signal.

During operation, the first temperature sensor 5 detects temperature inthe far-infrared heaters 1 and transmits the temperature to thecontroller 2 in the form of signal; meanwhile, the humidity sensor 6detects humidity of gas discharged from the clothes-drying drum andtransmits the humidity to the controller 2 in the form of signal.

The controller 2 compares the received temperature in the far-infraredheaters with a preset upper limit temperature Tmax1 and a preset lowerlimit temperature Tmin1, controls the relay 3 to be turned off when thetemperature in the far-infrared heaters is higher than the preset upperlimit temperature Tmax1, and controls the relay 3 to be turned on whenthe temperature in the far-infrared heaters is lower than the presetlower limit temperature Tmin1; and meanwhile, the controller 2 comparesthe received humidity value with a preset humidity value, and controlsthe relay 3 to be turned off and terminates a drying process when thehumidity value is less than the preset humidity value.

Since the far-infrared heater 1 itself has a temperature limitingcharacteristic (temperatures are different according to different TCMsystems, generally 200-400° C.) and a high degree of consistency; thecontrol system no longer adopts a mechanical temperature controller, butonly one first temperature sensor 5 is mounted on one far-infraredheater 1 for detecting and controlling temperature. Specifically, thefirst temperature sensor 5 is mounted inside the far-infrared heater 1;current of the far-infrared heaters 1 has a characteristic of increasinggradually; all the far-infrared heaters 1 are controlled by only onerelay 3, rather than respectively controlled by a plurality of relays 3.In this way, the system can control all the far-infrared heaters 1 byusing only one first temperature sensor 5 and one relay 3, to simplifycircuits and also save cost.

In the present embodiment, the far-infrared heaters 1 can be mounted onthe clothes-drying drum or mounted between the clothes-drying drum andthe tank body. When the far-infrared heaters 1 are mounted on theclothes-drying drum, mounting holes are arranged in the clothes-dryingdrum; and the far-infrared heaters 1 are mounted in the mounting holesso as to heat interior of the clothes-drying drum.

In the present embodiment, as another solution, when the far-infraredheaters 1 are mounted between the clothes-drying drum and the tank body,at least one group of hole arrays is arranged on the clothes-dryingdrum; each group of the hole arrays is composed of a plurality of holes;and the far-infrared heaters 1 are arranged outside the hole arrays, andcan heat interior of the clothes-drying drum through the hole arrays.

Since normal operation temperature of the far-infrared heaters used inthe clothes-drying system in the existing art is 600° C. and may reachto 1000° C. under abnormal conditions, control of the temperature isparticularly important; besides the above-mentioned temperaturedetection and protection for the far-infrared heaters, a temperaturesensor is further arranged in the clothes-drying drum; the temperaturesensor is configured to detect the temperature in the clothes-dryingdrum and prevent clothes from being damaged due to excessively hightemperature in the clothes-drying drum, which requires the whole machineto be equipped with a high-power fan, so as to make the temperature inthe drum as even as possible, so that security problems may occur whenan air speed is slightly lower, or an air duct is slightly blocked.

In the control system, the far-infrared heaters 1 are configured to heatclothes; the temperature of the far-infrared heaters 1 is locked, e.g.,the temperature of a 200 membrane system is not higher than 200° C., andthe far-infrared heaters are automatically powered off when thetemperature exceeds 200° C.; furthermore, the clothes are not heated byan air medium, but water of the clothes is directly heated by emittedfar-infrared radiation; these two aspects ensure use security firstly,so the temperature sensor arranged in the clothes-drying drum in atraditional clothes-drying system is no longer so important, andtemperature detection accuracy in the clothes-drying drum is no longerdependent on the air speed. However, for the clothes to be dried, if theclothes are made of chemical fibers, wools and other fabrics with hightemperature requirements, the requirements for the temperature in theclothes-drying drum are also relatively high.

Therefore, in the present embodiment, as a solution, at least one secondtemperature sensor 7 is further arranged on the clothes dryer; thesecond temperature sensor 7 is connected with the input end of thecontroller 2, for detecting the temperature in the clothes-drying drumand transmitting the temperature to the controller 2; the controller 2compares the received temperature in the clothes-drying drum with apreset upper limit temperature Tmax2 and a preset lower limittemperature Tmin2, controls the relay 3 to be turned off when thetemperature in the clothes-drying drum is higher than the preset upperlimit temperature Tmax2, and controls the relay 3 to be turned on whenthe temperature inside the clothes-drying drum is lower than the presetlower limit temperature Tmin2.

In the present embodiment, as a solution, the second temperature sensor7 is arranged at an air outlet of the clothes dryer.

In the present embodiment, the number of the second temperature sensors7 is at least one; when the number of the second temperature sensors 7is plural, after all the second temperature sensors 7 transmit thedetected temperatures in the clothes-drying drum to the controller 2;the controller 2 averages all the received temperatures in theclothes-drying drum, and then compares an average value with the presetupper limit temperature Tmax2 and the preset lower limit temperatureTmin2.

In the present embodiment, as a solution, a fan 8 is arranged at an airinlet of the clothes dryer; power of the fan 8 is 10-20 W; the fan 8 isconnected with the controller 2; and the controller 2 controls rotationof the fan 8. Since the control system avoids dependence on air speed,the use of the high-power fan is avoided, and only one smaller fan isrequired for auxiliary dehumidification; and therefore, noise of suchclothes dryer is low.

In the present embodiment, since a low-power fan is used in the controlsystem, hot and humid gas may be aggregated toward the air outlet at thetop of the clothes dryer; and therefore, as a solution, the humiditysensor 6 is placed at the air outlet of the clothes dryer in order tomore accurately measure the humidity.

In the present embodiment, as a solution, the controller 2 is made intoa PCB integrated circuit board.

Embodiments of Method

The present disclosure also provides a clothes-drying control methodusing far-infrared heating; the clothes-drying control method is appliedto a clothes dryer using far-infrared heating in which a firsttemperature sensor 5 and a humidity sensor 6 are arranged but the secondtemperature sensor 7 is not arranged; FIG. 2 is a flow chartillustrating a clothes-drying control method provided by methodembodiments of the present disclosure; and as shown in FIG. 2, thecontrol method includes the following steps.

In S11, after a drying process is started, the first temperature sensor5 detects temperature in a far-infrared heater 1 and transmits thetemperature to a controller 2 in the form of signal; meanwhile thehumidity sensor 6 detects humidity of gas in a clothes-drying drum andtransmits the humidity to the controller 2 in the form of signal;

in S12, the controller 2 compares a received humidity value with apreset humidity value; when the humidity value is less than or equal tothe preset humidity value, it is indicated that clothes in theclothes-drying drum are dried, a step S13 is executed; and when thehumidity value is greater than the preset humidity value, a step S14 isexecuted;

in S13, the controller 2 judges whether the relay 3 is in an off state,and controls the relay 3 to be in the off state and terminates theentire drying process if the relay 3 is not in the off state;

in S14, the controller 2 compares the received temperature in thefar-infrared heater with a preset upper limit temperature Tmax1 and apreset lower limit temperature Tmin1; the step S13 is executed when thetemperature in the far-infrared heater is higher than the preset upperlimit temperature Tmax1; and a step S15 is executed when the temperaturein the far-infrared heater is lower than the preset lower limittemperature Tmin1; and the controller 2 makes no response when thetemperature in the far-infrared heater is lower than or equal to thepreset upper limit temperature Tmax1 and higher than or equal to thepreset upper limit temperature Tmax1; and

in S15, the controller 2 judges whether the relay 3 is in an on state;and if the relay 3 is not turned on, the controller 2 controls the relay3 to be turned on, and the far-infrared heater 1 re-emits infrared rays.

In the present embodiment, the preset upper limit temperature Tmax1 maybe in a range of 190° C.-210° C., but is not limited thereto and can bedetermined according to specific conditions; and the preset lower limittemperature Tmin1 may be in the range of 140° C.-160° C., but is notlimited thereto and can be determined according to specific conditions.

The present disclosure also provides another clothes-drying controlmethod using far-infrared heating; the control method is applied to aclothes dryer using far-infrared heating in which a first temperaturesensor 5 and a humidity sensor 6 are arranged and a second temperaturesensor 7 is arranged in the drum; and FIG. 3 is a flow chartillustrating a mode of a clothes-drying control method provided bymethod embodiments of the present disclosure; and as shown in FIG. 3,the control method includes the following steps.

In S21, after a drying process is started, the first temperature sensor5 detects temperature in a far-infrared heater 1 and transmits thetemperature to a controller 2 in the form of signal; the humidity sensor6 detects humidity of gas in a clothes-drying drum and transmits thehumidity to the controller 2 in the form of signal; meanwhile the secondtemperature sensor 7 detects temperature in the clothes-drying drum andtransmits the temperature to the controller 2 in the form of signal;

in S22, the controller 2 compares the received humidity value with apreset humidity value; when the humidity value is greater than thepreset humidity value, a step S24 is executed; and when the humidityvalue is less than or equal to the preset humidity value, it isindicated that clothes in the clothes-drying drum are dried, a step S23is executed;

in S23, the controller 2 judges whether the relay 3 is in an off state,and controls the relay 3 to be in the off state and terminates theentire drying process if the relay 3 is not in the off state;

in S24, the controller 2 compares the received temperature in thefar-infrared heater with a preset upper limit temperature Tmax1 and apreset lower limit temperature Tmin1, and compares the receivedtemperature in the clothes-drying drum with a preset upper limittemperature Tmax2 and a preset lower limit temperature Tmin2; when atleast one of conditions that the temperature in the far-infrared heateris higher than the preset upper limit temperature Tmax1 and thetemperature in the clothes-drying drum is higher than the preset upperlimit temperature Tmax2 is satisfied, it is indicated that thetemperature in the clothes-drying drum and/or the temperature in thefar-infrared heater 1 is too high, the step S23 is executed to preventclothes and/or the far-infrared heater 1 from being burnt out; when atleast one of conditions that the temperature in the far-infrared heateris lower than the preset lower limit temperature Tmin1 and thetemperature in the clothes-drying drum is lower than the preset lowerlimit temperature Tmin2 is satisfied, it is indicated that thetemperature in the clothes-drying drum and/or the temperature in thefar-infrared heater 1 is too low, the step S25 is executed; or else, thecontroller 2 makes no response.

in S25, the controller 2 judges whether the relay 3 is in an on state;and if the relay 3 is not in the on state, the controller 2 controls therelay 3 to be turned on, and the far-infrared heater 1 re-emits infraredrays to continue to heat the clothes in the clothes-drying drum.

It should be noted that the above is only embodiments and appliedtechnical principles of the present disclosure. Those skilled in the artshould understand that the present disclosure is not limited to specificembodiments described herein. For those skilled in the art, the presentdisclosure may be subjected to various apparent changes, re-adjustmentsand substitutions without departing from a protection scope of thepresent disclosure. Thus, although the present disclosure is describedin detail through the above embodiments, the present disclosure is notonly limited to the above embodiments, but may include many otherequivalent embodiments without departing from conceptions of the presentdisclosure; and the scope of the present disclosure is determined by thescope of appended claims.

What is claimed is:
 1. A clothes dryer using far-infrared heating,comprising a clothes-drying drum, and further comprising at least onefar-infrared heater, a humidity sensor for detecting exhaust humidity ofthe clothes-drying drum, a relay and a controller having an output endconnected with the relay; wherein all the far-infrared heaters areconnected with a power supply through the relay; a first temperaturesensor is mounted inside one of the far-infrared heaters; the firsttemperature sensor and the humidity sensor are connected with an inputend of the controller; and the controller controls on and off of therelay according to a received temperature signal or humidity signal. 2.The clothes dryer using far-infrared heating according to claim 1,further comprising at least one second temperature sensor for detectingtemperature inside the clothes-drying drum, wherein the secondtemperature sensor is connected with the input end of the controller. 3.The clothes dryer using far-infrared heating according to claim 2,wherein the second temperature sensor is arranged at an air outlet ofthe clothes dryer.
 4. The clothes dryer using far-infrared heatingaccording to claim 1, wherein the humidity sensor is arranged at the airoutlet of the clothes dryer.
 5. The clothes dryer using far-infraredheating according to claim 1, wherein a fan is arranged at an air inletof the clothes dryer; power of the fan is 10-20 W; and the fan isconnected with the controller.
 6. The clothes dryer using far-infraredheating according to claim 1, wherein mounting holes are arranged in theclothes-drying drum; and the far-infrared heaters are mounted in themounting holes for heating interior of the clothes-drying drum.
 7. Theclothes dryer using far-infrared heating according to claim 1, whereinat least one group of hole arrays are arranged on the clothes-dryingdrum; each group of the hole arrays is composed of a plurality of holes;and the far-infrared heaters are arranged outside the hole arrays, andcan heat interior of the clothes-drying drum through the hole arrays. 8.A clothes-drying control method using far-infrared heating, applied tothe clothes dryer using far-infrared heating according to claim 1,comprising following steps: in S11, detecting, by a first temperaturesensor, temperature in a far-infrared heater and transmitting thetemperature to a controller in the form of signal; meanwhile detecting,by a humidity sensor, humidity of gas in a clothes-drying drum andtransmitting the humidity to the controller in the form of signal; inS12, comparing, by the controller, the received humidity value with apreset humidity value; executing a step S14 when the humidity value isgreater than the preset humidity value; and executing a step S13 whenthe humidity value is less than or equal to the preset humidity value;in S13, controlling a relay to be in an off state by the controller; inS14, comparing, by the controller, the received temperature in thefar-infrared heater with a preset upper limit temperature Tmax1 and apreset lower limit temperature Tmin1; executing the step S13 when thetemperature in the far-infrared heater is higher than the preset upperlimit temperature Tmax1; and executing a step S15 when the temperaturein the far-infrared heater is lower than the preset lower limittemperature Tmin1; and in S15, controlling the relay to be in an onstate by the controller.
 9. A clothes-drying control method usingfar-infrared heating, applied to the clothes dryer using far-infraredheating according to claim 2, comprising following steps: in S21,detecting, by a first temperature sensor, temperature in a far-infraredheater and transmitting the temperature to a controller in the form ofsignal; detecting, by a humidity sensor, humidity of gas in aclothes-drying drum and transmitting the humidity to the controller inthe form of signal; meanwhile detecting, by a second temperature sensor,the temperature in the clothes-drying drum and transmitting thetemperature to the controller in the form of signal; in S22, comparing,by the controller, the received humidity value with a preset humidityvalue; executing a step S24 when the humidity value is greater than thepreset humidity value; and executing a step S23 when the humidity valueis less than or equal to the preset humidity value; in S23, controllinga relay to be in an off state by the controller; in S24, comparing, bythe controller, the received temperature in the far-infrared heater witha preset upper limit temperature Tmax1 and a preset lower limittemperature Tmin1, and comparing the received temperature in theclothes-drying drum with a preset upper limit temperature Tmax2 and apreset lower limit temperature Tmin2; executing the step S23 when atleast one of conditions that the temperature in the far-infrared heateris higher than the preset upper limit temperature Tmax1, and thetemperature in the clothes-drying drum is higher than the preset upperlimit temperature Tmax2 is satisfied; and executing a step S25 when atleast one of conditions that the temperature in the far-infrared heateris lower than the preset lower limit temperature Tmin1, and thetemperature in the clothes-drying drum is lower than the preset lowerlimit temperature Tmin2 is satisfied; and in S25, controlling the relayto be in an on state by the controller.